Packages are folders that are identified by the interpreter by the presence of a file named
__init__.py. Packages work as collections to organize hierarchically modules.
You can import all package modules using the statement
from packagename import *.
__init__.py file can be empty or contain package initialization code or define a variable called
__all__, a list of modules of the package that will be imported when using "*". Without the file, Python does not recognize the folder as a valid packet.